Tube rack



FIG. 1 is a front perspective view of a tube rack showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a front elevational view thereof; and,

FIG. 7 is a rear elevational view thereof.

The broken lines depict portions of the tube rack that form no part ofthe claimed design.

CLAIM The ornamental design for a tube rack, as shown and described.